I have lumps behind my ears. big swollen hard lumps. could it be swollen lymph nodes? what could cause this?

Lumps-Head and Neck: Many possibilities- lymph nodes are among them, but so are skin lesions, cysts, salivary tumors and more unusual things like angiolymphoid hyperplasia with eosinophilia. Correlation with other symptoms, duration, pain, mobility could help narrow the dx. A fine needle biopsy might be needed if no obviously benign cause is found clinically.